3.9 mOhm Rds(on) — why it matters for the rail
The TPS22990NDMLT is a single-channel, high-side load switch from Texas Instruments, built around an N-channel MOSFET with a typical on-resistance of 3.9 mOhm. At 10 A continuous output, that translates to under 0.4 W conduction loss at 25°C — the thermal budget stays low enough that the 10-WSON package with exposed pad can handle it without forced airflow in most industrial enclosures. That simplifies the BOM: no external charge-pump or bootstrap components.
Power Good and slew-rate control — sequencing without a supervisor
The integrated Power Good output asserts when the switch output rises above a threshold, giving the downstream load a valid-rail indicator. The slew-rate control limits inrush current during turn-on, which matters when the load includes large decoupling caps or a hot-plug card that could otherwise droop the upstream rail.
Package and footprint — what the 10-WSON needs
The datasheet layout note calls for a 2.2 mm x 1.5 mm copper pad under the package, connected to the GND plane with at least four vias. Without that thermal relief, the 10 A rating derates significantly above 85°C ambient.